: Aim 1 is to delineate the role of changes in subunit gene transcription rates in the expression of gonadotropin subunits, GnRH receptor (GnRH-R) and activin beta-B mRNAs. Aim 2 is to investigate the intracellular (3rd) messenger mechanisms that mediate GnRH/Ca pulse frequency regulation of differential expression of gonadotrope genes and will: 1) assess the effects of blockade of PKA, PKC, CAMKII, and MAPK on transcriptional and mRNA responses different frequency GnRH or Ca pulses; 2) assess activation of PKA, PKC, CAMKII, and MAPKs after Ca or GnRH pulses. Aim 3 will investigate the MAPK pathways (ERK, JNK, p38) involved in GnRH stimulation of gonadotrope gene expression.